/*
 *  Simbad - Robot Simulator
 *  Copyright (C) 2004 Louis Hugues
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, 
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 -----------------------------------------------------------------------------
 * $Author: sioulseuguh $ 
 * $Date: 2005/04/25 17:54:58 $
 * $Revision: 1.5 $
 * $Source: /cvsroot/simbad/src/simbad/sim/Device.java,v $
 * 
 * BUGFIX - Louis - 30/12/2006  force udpate of sensor after a reset.
 */
package simbad.sim;

import javax.swing.JPanel;

/**
 * A abstract device, base class for sensorDevice and ActuatorDevice. The class
 * manages an update rate which will be used by the simulator.
 */
public abstract class Device extends BaseObject {

	private SimpleAgent owner;
	private String name;
	private double updatePerSecond;
	private double elapsedSinceUpdate;
	private boolean firstUpdate;
	private boolean updateOnEachFrame;

	Device() {
		owner = null;
		name = "<name>";
		updatePerSecond = 1.0;
		elapsedSinceUpdate = 0.0;
		firstUpdate = true;
		updateOnEachFrame = false;
	}

	/**
	 * @return device's name .
	 */
	public String getName() {
		return name;
	}

	protected void setName(String name) {
		this.name = name;
	}

	/** Set the agent owner of this device */
	protected void setOwner(SimpleAgent agent) {
		this.owner = agent;
	}

	/** Get the agent owner of this device */
	protected SimpleAgent getOwner() {
		return this.owner;
	}

	/**
	 * Creates the panel associated to the device. This panel can be inserted in
	 * the inspector window for monitoring.
	 * 
	 * @return the JPanel. null if no panel can be associated
	 */
	public JPanel createInspectorPanel() {
		return null;
	}

	/** Sets the number of update per seconds for this sensor. */
	public void setUpdatePerSecond(double ups) {
		updatePerSecond = ups;
	}

	/** Sets if update happens on each frame . */
	public void setUpdateOnEachFrame(boolean on) {
		updateOnEachFrame = on;
	}

	/**
	 * Returns the number of updates per second requested for this sensor.
	 * 
	 * @return requested number of update per second (in virtual time).
	 */
	public double getUpdatePerSecond() {
		return updatePerSecond;
	}

	/** to be overriden */
	protected void update() {
	}

	/** to be overriden */
	protected void reset() {
		// BUGFIX 30/12/2006
		// we want to be sure that sensors/device will be updated immediately
		// after a reset
		firstUpdate = true;
	}

	/** Called by the simulator loop */
	protected void update(double elapsedSeconds) {
		if (updateOnEachFrame) {
			update();
		} else {
			elapsedSinceUpdate += elapsedSeconds;
			double delta = 1.0 / updatePerSecond;
			if ((elapsedSinceUpdate > delta) || (firstUpdate)) {
				update();
				elapsedSinceUpdate -= delta;
				firstUpdate = false;
			}
		}
	}

}